Repsol Sa plans to increase production in the Marcellus natural gas shale field by about 50 percent by the end of 2020 due to efficiency gains, according to an executive comment at an industry conference in New York on Thursday.

“With just the addition of one rig and investment of about $400 million a year, we’re going to be able to raise production by 50 percent and be cumulative cash flow positive by the end of 2020,” Paul Ferneyhough, executive director of North America for Repsol said at the S&P Global Platts Global Energy Outlook Forum.

The company holds an interest in 168,400 net acres in the Marcellus Shale.

Learn more: Reuters > Repsol expects to raise production by about 50 percent in Marcellus shale by end of 2020